Nakdong Estuary Barrage and Land Reclamation – Morphological Aspects

1984 ◽  
Vol 16 (1-2) ◽  
pp. 233-241 ◽  
Author(s):  
W D Eysink
Keyword(s):  
Land Reclamation ◽  
Morphological Changes ◽  
Ecological Impact ◽  
Flow Conditions ◽  
Cross Sectional ◽  
National Monument ◽  
Morphological Aspects ◽  
Maintenance Dredging ◽  
Time Required ◽  
Official Status

The construction of the barrage will change the flow conditions in the entire estuary which will interfere in the present equilibrium between channel dimensions and flow conditions. Consequently, morphological changes in the estuary have to be taken into account. Generally, the cross sectional area of a tidal channel shows a distinct relationship with a characteristic tidal prism passing that section. Also here such a relation could be found and was applied to predict the new equilibrium state of the estuary. Estimates of the time required for adaptation have been based on the total sediment volumes required for this and the future sediment transport pattern which must supply those volumes. The morphological study provided a basis for proper decisions on matters such as: selection of the barrage location, maintenance dredging and levee heights. It also gave the effects of the barrage on the tidal-flat area which, as an important bird habitat, has the official status of a national monument. In particular these effects and the aspects of maintenance dredging seaward of the barrage are discussed as they are major phenomena for the ecological impact of the barrage.

scholarly journals A Numerical Study of Sub-Millisecond Integrated Mix-and-Inject Microfluidic Devices for Sample Delivery at Synchrotron and XFELs

2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey
Keyword(s):  
Molecular Dynamics ◽  
Flow Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Liquid Jets ◽  
Mixing Efficiency ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Time Required

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.

scholarly journals Evidence for diagnosis of early chronic pancreatitis after three episodes of acute pancreatitis: a cross-sectional multicentre international study with experimental animal model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Péter J. Hegyi ◽  
Alexandra Soós ◽  
Emese Tóth ◽  
Attila Ébert ◽  
Viktória Venglovecz ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Chronic Pancreatitis ◽  
Morphological Changes ◽  
International Study ◽  
Study Data ◽  
Cross Sectional ◽  
Clinical Biomarkers ◽  
Stage Disease ◽  
Significant Difference ◽  
End Stage

AbstractChronic pancreatitis (CP) is an end-stage disease with no specific therapy; therefore, an early diagnosis is of crucial importance. In this study, data from 1315 and 318 patients were analysed from acute pancreatitis (AP) and CP registries, respectively. The population from the AP registry was divided into AP (n = 983), recurrent AP (RAP, n = 270) and CP (n = 62) groups. The prevalence of CP in combination with AP, RAP2, RAP3, RAP4 and RAP5 + was 0%, 1%, 16%, 50% and 47%, respectively, suggesting that three or more episodes of AP is a strong risk factor for CP. Laboratory, imaging and clinical biomarkers highlighted that patients with RAP3 + do not show a significant difference between RAPs and CP. Data from CP registries showed 98% of patients had at least one AP and the average number of episodes was four. We mimicked the human RAPs in a mouse model and found that three or more episodes of AP cause early chronic-like morphological changes in the pancreas. We concluded that three or more attacks of AP with no morphological changes to the pancreas could be considered as early CP (ECP).The new diagnostic criteria for ECP allow the majority of CP patients to be diagnosed earlier. They can be used in hospitals with no additional costs in healthcare.

Research of the flow procedures in a pressure sewer system

2003 ◽  
Vol 47 (7-8) ◽  
pp. 351-356
Author(s):  
C. Dohse ◽  
H. Eckstädt
Keyword(s):  
Land Reclamation ◽  
Flow Conditions ◽  
Sewer System ◽  
Flow Meters ◽  
Initial Information ◽  
Pressure Pipe ◽  
Pumping Stations ◽  
Hydraulic Conditions ◽  
Measuring Section ◽  
The University

At the Institute of Land Reclamation, Hydrology and Sanitary Engineering of the University at Rostock the pressure and flow ratios are examined within a measuring section in the pressure dewatering system on the Darfl peninsula. The objective of the research project is the knowledge upgrade about the highly unsteady hydraulic conditions in a pressure sewer system. This paper firstly presents the method and the dimensioning of pressure dewatering systems, which can be done using either the peak effluent method or the statistical method; the examination program will be explained. The examination includes pressure difference measuring with two pressure meters and flow data measuring via magnetic-inductive flow meters. Additionally the pump running times of 15 pumping stations, as well as the compressor action of the pressure pipe rinsing station are continuously and temporarily recorded and saved. Finally the measuring results which provide initial information about the pressure and flow conditions in a pressure dewatering system will be presented. The effects of the rinsing, the low pressure differences, the air cushions, the seasonal differences as well as the daily development graphs of the wastewater production are all clearly visible.

Prediction of Fluid Flow in Artificial Cancellous Bone

2014 ◽  
Vol 695 ◽  
pp. 393-397
Author(s):  
Elsa Syuhada Abdull Yamin ◽  
Nor Azwadi Che Sidik
Keyword(s):  
Fluid Flow ◽  
Pore Size ◽  
Surface Area ◽  
Pore Diameter ◽  
Bone Surface ◽  
Flow Conditions ◽  
Morphological Aspects ◽  
Flow Through ◽  
Structure Result ◽  
Dynamics Method

The permeability of the blood in the artificial cancellous are affected by certain morphological aspects that include pore diameter, pore size, porosity and the bone surface area. In this study, computational fluid dynamics method is used to study the fluid flow through the cancellous structure. Result of the present work show that geometries with the same porosity and overall volume can have different permeability due to the differences in bone surface area. The hexahedron geometry has the highest permeability under stimulated blood flow conditions, where the cylindrical geometry has the lowest. Linear relationship is found between permeability and the two physical properties, bone surface area and the pore size.

scholarly journals POST PARTUM HEMORRHAGE;

2017 ◽  
Vol 24 (09) ◽  
pp. 1347-1353
Author(s):  
Sardar Alfareed Zafar ◽  
Asim Shaukat ◽  
Ayesha Khalid ◽  
Ammara Niaz ◽  
Shagufta Noor
Keyword(s):  
Medical Therapy ◽  
Post Partum ◽  
Young Patients ◽  
Reproductive Capacity ◽  
Cross Sectional ◽  
Vaginal Deliveries ◽  
Future Fertility ◽  
Third Stage ◽  
Conventional Medical Therapy ◽  
Time Required

Primary postpartum hemorrhagic, rightly called as obstetrician’s nightmare,refers to excessive blood loss of more than 500ml during the third stage of labour or in the first24 hours after delivery. It continues to be one of the leading causes of maternal mortality andmorbidity all over the world including Pakistan where it is responsible for 21-31% of maternalmortality and morbidity. Objectives: Objective of study was to determine the efficacy of balloontamponade in the management of primary PPH, so that a low cast, easy to use technology isavailable for conserving future fertility by treating postpartum hemorrhage. Settings: Departmentof Gynae & Obs, Allied Hospital, Faisalabad. Study Design: Descriptive cross sectional study.Study Period: 6 months from 1st Oct, 2015 to 31st March, 2016. Material & Methods: All patientsdelivered vaginally at term (after 37 completed weeks of gestation) who developed PPH due touterine atony after failure of conventional medical therapy were included in this study. Patientselection was based on inclusion and exclusion criteria. Their demographic profile and efficacyof balloon tamponade was checked in terms of time required to control hemorrahage andneed of laparotomy. Results: During study period total no. Of vaginal deliveries were 3000.Out of these 298 developed PPH, 220 had PPH due to uterine atony and did not respond toconventional medical therapy. The age of patients ranged between 22 and 40 years with meanage of 30 year (±4.88SD). The parity of the patients ranged between 1 and 14 with the meanparity of 4 (±2.26SD). The condom catheter was introduced in all the selected 80 patients andwas successful in 73 patients. Conclusions: In developing countries such as Pakistan wherethe maternal death rate from PPH is very high, this safe, in expensive and easy procedure (itdoes not require any expertise) can be applied in any situation to save a life and to save theuterus in young patients to conserve reproductive capacity and prevent them from surgery andits morbidity. This will protect the patients from irreversible shock and even death with a successrate of 85-95%.

Nerve Hypertrophy and Altered Diffusion in Anti-Myelin-Associated Glycoprotein Neuropathy Detected by Brachial Plexus Magnetic Resonance Neurography

2021 ◽  
pp. 1-9
Author(s):  
Kyosuke Koide ◽  
Atsuhiko Sugiyama ◽  
Hajime Yokota ◽  
Hiroki Mukai ◽  
Jiaqi Wang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Brachial Plexus ◽  
Diffusion Tensor ◽  
Morphological Changes ◽  
Mean Diffusivity ◽  
Nerve Roots ◽  
Magnetic Resonance Neurography ◽  
Cross Sectional ◽  
3 Dimensional ◽  
Myelin Associated Glycoprotein

<b><i>Introduction:</i></b> This study assessed the morphological changes and diffusion tensor imaging (DTI)-derived parameters of the brachial plexus using magnetic resonance neurography (MRN) in patients with anti-myelin-associated glycoprotein (anti-MAG) neuropathy. <b><i>Methods:</i></b> Eight patients with anti-MAG neuropathy underwent MRN of the brachial plexus with 3-dimensional (3D) short tau inversion recovery (STIR) and DTI sequences. Two neuroradiologists and a neurologist qualitatively assessed nerve hypertrophy on 3D STIR MRN. The cross-sectional area (CSA) of the nerve roots was measured. Quantitative analyses of fractional anisotropy (FA) and axial, radial, and mean diffusivity (AD, RD, and MD) were obtained after postprocessing on DTI and manual segmentation. <b><i>Results:</i></b> There was nerve hypertrophy in 37.5% of the patients with anti-MAG neuropathy. All patients with anti-MAG neuropathy with nerve hypertrophy were refractory to rituximab therapy. The CSA of the nerve roots was inversely correlated with FA and positively correlated with MD and RD. FA decreased in the nerve roots and inversely correlated with disease duration. <b><i>Conclusions:</i></b> Nerve hypertrophy appears in the proximal portion of peripheral nerves, such as the brachial plexus, in patients with anti-MAG neuropathy. Altered diffusion in the nerve roots might be associated with the loss of myelin integrity due to the demyelination process in anti-MAG neuropathy.

Alveolar pressure-airflow characteristics in humans breathing air, He-O2, and SF6-O2

1981 ◽  
Vol 51 (4) ◽  
pp. 1033-1037 ◽  
Author(s):  
A. S. Slutsky ◽  
J. M. Drazen ◽  
C. F. O'Cain ◽  
R. H. Ingram
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Coefficient Of Friction ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Sectional Area ◽  
Alveolar Pressure ◽  
Flow Conditions ◽  
Cross Sectional ◽  
The Coefficient Of Friction

In a system of rigid tubes under steady flow conditions, the coefficient of friction [CF = 2 delta P/(rho V2/A2)] (where delta P is pressure drop, rho is density, V is flow, and A is cross-sectional area) should be a unique function of Reynolds' number (Re). Recently it has been shown that at any given Re, the value of CF using transpulmonary pressure (PL) was lower when breathing He-O2 compared with air (Lisboa et al., J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 48: 878–885, 1980). One explanation for this discontinuity is that PL includes the pressure drop due to tissue viscance, which is independent of V, and thus would lead to an overestimate of CF on air compared with He-O2 at any Re. We tested this hypothesis by measuring V related to alveolar pressure, rather than PL, in normal subjects breathing air, He-O2, and SF6-O2. In each subject, for a given Re, CF was greatest breathing SF6-O2 and lowest breathing He-O2, similar to results using PL. Thus tissue viscance is not the sole cause of the discontinuous plot of CF vs. Re, and this phenomenon must be due to other factors, such as changing geometry or nonsteady behavior.

Dynamics of the Tracheal Airway and Its Influences on Respiratory Airflows: An Exemplar Study

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Bora Sul ◽  
Talissa Altes ◽  
Kai Ruppert ◽  
Kun Qing ◽  
Daniel S. Hariprasad ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Minute Ventilation ◽  
Correlation Coefficients ◽  
Dynamic Imaging ◽  
Imaging Data ◽  
Cross Sectional ◽  
Mild Conditions ◽  
Large Airways ◽  
Magnetic Resonance Imaging Mri

Respiration is a dynamic process accompanied by morphological changes in the airways. Although deformation of large airways is expected to exacerbate pulmonary disease symptoms by obstructing airflow during increased minute ventilation, its quantitative effects on airflow characteristics remain unclear. Here, we used in vivo dynamic imaging and examined the effects of tracheal deformation on airflow characteristics under different conditions based on imaging data from a single healthy volunteer. First, we measured tracheal deformation profiles of a healthy lung using magnetic resonance imaging (MRI) during forced exhalation, which we simulated to characterize the subject-specific airflow patterns. Subsequently, for both inhalation and exhalation, we compared the airflows when the modeled deformation in tracheal cross-sectional area was 0% (rigid), 33% (mild), 50% (moderate), or 75% (severe). We quantified differences in airflow patterns between deformable and rigid airways by computing the correlation coefficients (R) and the root-mean-square of differences (Drms) between their velocity contours. For both inhalation and exhalation, airflow patterns were similar in all branches between the rigid and mild conditions (R > 0.9; Drms < 32%). However, airflow characteristics in the moderate and severe conditions differed markedly from those in the rigid and mild conditions in all lung branches, particularly for inhalation (moderate: R > 0.1, Drms < 76%; severe: R > 0.2, Drms < 96%). Our exemplar study supports the use of a rigid airway assumption to compute flows for mild deformation. For moderate or severe deformation, however, dynamic contraction should be considered, especially during inhalation, to accurately predict airflow and elucidate the underlying pulmonary pathology.

scholarly journals Compatibilization of Polypropylene/Polyamide 6 Blend Fibers Using Photo-Oxidized Polypropylene

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 81 ◽  
Author(s):  
Francesco La Mantia ◽  
Manuela Ceraulo ◽  
Maria Mistretta ◽  
Luigi Botta ◽  
Marco Morreale
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Morphological Changes ◽  
Elongational Flow ◽  
Polyamide 6 ◽  
Flow Conditions ◽  
Polyolefin Blends ◽  
Pp Blends ◽  
Oxidized Polypropylene

The use of polyamide/polyolefin blends has gained importance and concern for years, but they also show some issues to be adequately addressed, such as the incompatibility between the two components. This is usually overcome by using suitable compatibilizers, typically based on functionalized polyolefins. However, there is only little information about the use of a degraded polyolefins to induce compatibilization. This is even truer, as far as polyamide 6/polypropylene (PA6/PP) blends are concerned. In this work, compatibilization of PA6/PP blends by using small amounts of photo-oxidized PP was investigated; furthermore, the effects due to the presence of the photo-oxidized PP were studied also in relationship to the spinning operation, where the existence of the non-isothermal elongational flow can lead to significant, further morphological changes. It was found that isotropic samples showed significant enhancements of the tensile properties upon adding the photo-oxidized PP. Under non-isothermal elongational flow conditions, the presence of the photo-oxidized PP was particularly effective in improving the mechanical properties in comparison to the uncompatibilized blend fibers. Furthermore, an important result was found: The elongational-flow processing allowed obtaining anisotropic samples where the improvements of the properties, in comparison to the isotropic samples, were similar to those achieved by using a compatibilizer.

scholarly journals Morphological changes during early trans-tibial prosthetic fitting

1998 ◽  
Vol 22 (2) ◽  
pp. 115-122 ◽  
Author(s):  
M. Lilja ◽  
P. Hoffmann ◽  
T. Öberg
Keyword(s):  
Morphological Changes ◽  
Muscle Group ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Transtibial Amputation ◽  
Negative Power ◽  
Lateral Muscle ◽  
Amputation Stump ◽  
The Cross

Morphological changes in the amputation stump may have serious implications regarding the suspension and fit of the prosthetic socket. In an earlier study (Lilja and Öberg, 1997) the authors have shown that the volume of the transtibial amputation stump decreases according to a negative power function after amputation, and that the stump volume does not stabilise until four months after the operation. In the present study, Magnetic Resonance Imaging (MRI) technique was used to examine morphological changes in the amputation stump after transtibial amputation in a small number of cases. The authors expected to find a decrease in the cross-sectional area of the stump and of the separate muscles similar to the findings in earlier studies. However, two different patterns were found. The cross-sectional area of the entire stump as well as that of the medial muscle group changed according to the authors' hypothesis, i.e. an initial fast decrease, followed by a more moderate decrease of the area. In the lateral muscle group another pattern was found. After an initial rapid decrease the area increased, sometimes to a magnitude larger than the initial value. After the amputation the lateral muscle group may acquire a new function, contributing to the suspension of the socket. Despite the limited number of patients, this study presents findings which may be important in the clinical fitting of trans-tibial prostheses.

Sign in / Sign up

Export Citation Format

Share Document